Indaceno derivatives as organic semiconductors

ABSTRACT

The present invention provides compounds comprising at least one unit of formula (1) or (1′) as well as a process for the preparation of the compounds, intermediates of this process, electronic devices comprising the compounds, and the use of the compounds as semiconducting materials.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a national stage application under 35 U.S.C. § 371 of International Application No. PCT/EP2019/077446, filed internationally on Oct. 10, 2019, which claims priority to and benefit of European Patent Application No. 18200400.2, filed in the European Patent Office on Oct. 15, 2018, the entire contents of which are incorporated herein by reference.

The present invention relates to compounds, including polymers, a process for the preparation of these compounds, to intermediates of the process, to electronic devices comprising these compounds, as well as to the use of these compounds as semiconducting material.

Organic semiconducting materials can be used in electronic devices such as organic photovoltaic devices (OPVs), organic field-effect transistors (OFETs), organic light emitting diodes (OLEDs), organic photodiodes (OPDs) and organic electrochromic devices (ECDs).

It is desirable that the organic semiconducting materials are compatible with liquid processing techniques such as spin coating as liquid processing techniques are convenient from the point of processability, and thus allow the production of low cost organic semiconducting material-based electronic devices. In addition, liquid processing techniques are also compatible with plastic substrates, and thus allow the production of light weight and mechanically flexible organic semiconducting material-based electronic devices.

For application in organic photovoltaic devices (OPVs), organic field-effect transistors (OFETs), and organic photodiodes (OPDs), it is further desirable that the organic semiconducting materials show high charge carrier mobility and are of high stability under ambient conditions.

It was the object of the present invention to provide new and improved organic semiconducting materials.

This object is solved by the compounds of claim 1, the process of claim 12, the intermediates of claim 13, the electronic device of claim 15 and the use of the compounds of claim 17.

The compounds of the present invention comprise at least one unit of formula

-   -   wherein     -   M1 and M2 are independently of each other an aromatic or         heteroaromatic monocyclic or bicyclic ring system;     -   X is at each occurrence O, S, Se or Te,     -   Q is at each occurrence C, Si or Ge,     -   R¹ is at each occurrence selected from the group consisting of         H, C₁₋₅₀-alkyl,         —[CH₂]_(o)—[OSiR^(a)R^(a)]_(p)—OSiR^(a)R^(a)R^(a),         —[CH₂]_(o)—[R^(a)R^(a)Si—O]_(p)—SiR^(a)R^(a)R^(a),         —[CR^(b)R^(b)]_(q)—CR^(b)R^(b)R^(b), C₂₋₅₀-alkenyl,         C₂₋₅₀alkynyl, C₅₋₈-cycloalkyl, C₆₋₁₄-aryl and 5 to 14 membered         heteroaryl,         -   wherein         -   is an integer from 0 to 10,         -   p is an integer from 1 to 40,         -   R^(a) is at each occurrence C₁₋₁₀-alkyl, C₂₋₁₀-alkenyl or             C₂₋₁₀-alkynyl,         -   q is an integer from 1 to 50,         -   R^(b) is at each occurrence H or halogen, with the provisio             that not all R^(b) in —[CR^(b)R^(b)]_(q)—CR^(b)R^(b)R^(b)             are H,         -   C₁₋₅₀-alkyl, C₂₋₅₀-alkenyl and C₂₋₅₀-alkynyl can be             substituted with one to four substituents independently             selected from the group consisting of OR^(c), OC(O)—R^(c),             C(O)—OR^(c), C(O)—R^(c), NR^(c)R^(c), NR^(c)—C(O)R^(c),             C(O)—NR^(c)R^(c), N[C(O)R^(c)][C(O)R^(c)], SR^(c), CN,             —SiR^(c)R^(c)R^(c) and NO₂,         -   C₅₋₈-cycloalkyl can be substituted with one or two             substituents independently selected from the group             consisting of C₁₋₁₀-alkyl, C₂₋₁₀-alkenyl, C₂₋₁₀-alkynyl,             OR^(c), OC(O)—R^(c), C(O)—OR^(c), C(O)—R^(c), NR^(c)R^(c),             NR^(c)—C(O)R^(c), C(O)—NR^(c)R^(c), N[C(O)R^(c)][C(O)R^(c)],             SR^(c), halogen, CN, —SiR^(c)R^(c)R^(c) and NO₂; and one             CH₂-group of C₅₋₈-cycloalkyl can be replaced by O, S, OC(O),             CO, NR^(c) or NR^(c)—CO,         -   C₆₋₁₄-aryl and 5 to 14 membered heteroaryl can be             substituted with one to three substituents independently             selected from the group consisting of C₁₋₁₀-alkyl,             C₂₋₁₀-alkenyl, C₂₋₁₀-alkynyl, OR^(c), OC(O)—R^(c),             C(O)—OR^(c), C(O)—R^(c), NR^(c)R^(c), NR^(c)—C(O)R^(c),             C(O)—NR^(c)R^(c), N[C(O)R^(c)][C(O)R^(c)], SR^(c), halogen,             CN, and NO₂,             -   wherein             -   R^(c) is at each occurrence H, C₁₋₂₀-alkyl,                 C₂₋₁₀-alkenyl or C₂₋₁₀-alkynyl,     -   R² is at each occurrence H, C₁₋₃₀-alkyl, C₂₋₃₀-alkenyl or         C₂₋₃₀-alkynyl or halogen,     -   n is 0, 1, 2, 3 or 4,     -   m is 0, 1, 2, 3 or 4,     -   L¹ and L² are independently from each other and at each         occurrence selected from the group consisting of C₆₋₂₆-arylene,         5 to 20 membered heteroarylene,

-   -   -   wherein         -   C₆₋₂₆-arylene and 5 to 20 membered heteroarylene can be             substituted with one to four substituents R^(d) at each             occurrence selected from the group consisting of H,             C₁₋₃₀-alkyl, C₂₋₃₀-alkenyl, C₂₋₃₀-alkynyl and halogen, and

-   -   -   can be substituted with one or two substituents at each             occurrence selected from the group consisting of R^(e),             COOR^(e) and CN, wherein R^(e) is at each occurrence             selected from the group consisting of H, C₁₋₃₀-alkyl,             C₂₋₃₀-alkenyl and C₂₋₃₀-alkynyl.

    -   C₁₋₁₀-alkyl, C₁₋₂₀-alkyl, C₁₋₃₀-alkyl and C₁₋₅₀-alkyl can be         branched or unbranched. Examples of C₁₋₁₀-alkyl are methyl,         ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl,         tert-butyl, n-pentyl, neopentyl, isopentyl, n-(1-ethyl)propyl,         n-hexyl, n-heptyl, n-octyl, n-(2-ethyl)hexyl, n-nonyl and         n-decyl. Examples of C₁₋₂₀-alkyl are C₁₋₁₀-alkyl and n-undecyl,         n-dodecyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl,         n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl,         n-nonadecyl and n-icosyl (C₂₀). Examples of C₁₋₃₀-alkyl and         C₁₋₅₀-alkyl are C₁₋₂₀-alkyl and n-docosyl (C₂₂), n-tetracosyl         (C₂₄), n-hexacosyl (C₂₆), n-octacosyl (C₂) and n-triacontyl         (C₃₀).

    -   C₂₋₁₀-alkenyl, C₂₋₂₀-alkenyl, C₂₋₃₀-alkenyl and C₂₋₅₀-alkenyl         can be branched or unbranched. Examples of C₁₋₂₀-alkenyl are         vinyl, propenyl, cis-2-butenyl, trans-2-butenyl, 3-butenyl,         cis-2-pentenyl, trans-2-pentenyl, cis-3-pentenyl,         trans-3-pentenyl, 4-pentenyl, 2-methyl-3-butenyl, hexenyl,         heptenyl, octenyl, nonenyl and docenyl. Examples of         C₂₋₂₀-alkenyl are C₂₋₁₀-alkenyl and linoleyl (C₁₈), linolenyl         (C₁₈), oleyl (C₁₈), and arachidonyl (C₂₀). Examples of         C₂₋₅₀alkenyl are C₂₋₂₀-alkenyl and erucyl (C₂₂).

    -   C₂₋₁₀-alkynyl, C₂₋₂₀-alkynyl and C₂₋₅₀-alkynyl can be branched         or unbranched. Examples of C₂₋₁₀-alkynyl are ethynyl,         2-propynyl, 2-butynyl, 3-butynyl, pentynyl, hexynyl, heptynyl,         octynyl, nonynyl and decynyl. Examples of C₂₋₂₀-alkynyl and         C₂₋₅₀alkynyl are undecynyl, dodecynyl, undecynyl, dodecynyl,         tridecynyl, tetradecynyl, pentadecynyl, hexadecynyl,         heptadecynyl, octadecynyl, nonadecynyl and icosynyl (C₂₀).

Examples of C₅₋₈-cycloalkyl are cyclopentyl, cyclohexyl, cycloheptyl and cyclooctyl.

Halogen can be F, Cl, Br and I.

C₆₋₁₄-aryl is a 6 to 14 membered monocyclic or polycyclic, such as dicyclic, tricyclic, ring system, wherein the rings are either condensed to each other or connected via a double bond, which C₆₋₁₄-aryl comprises at least one C-aromatic ring, and which C₆₋₁₄-aryl may also comprise non-aromatic rings, which non-aromatic rings may comprise heteroatoms such as O, S, Se, Te, Si, N and Ge, and which C-aromatic rings or non-aromatic ring may be substituted, for example by C₁₋₃₀-alkyl, ═O, ═C(C₁₋₃₀-alkyl)₂ or ═C(CN)₂.

Examples of C₆₋₁₄-aryl are

5 to 14 membered heteroaryl is a 5 to 14 membered monocyclic or polycyclic, such as dicyclic, tricyclic or tetracyclic, ring system, wherein the rings are either condensed to each other or connected via a double bond, which 5 to 14 membered heteroaryl comprises at least one heteroaromatic ring having at least one heteroatom selected from the group consisting of O, S, Se, N and Te, and which 5 to 14 membered heteroaryl may also comprise aromatic carbon rings or non-aromatic rings, which non-aromatic ring may comprise heteroatoms such as O, S, Se, Te, Si, N and Ge, and which heteroaromatic rings, aromatic carbon rings or non-aromatic rings may be substituted, for example by C₁₋₃₀-alkyl, ═O, ═C(C₁₋₃₀-alkyl)₂ or ═C(CN)₂.

Examples of 5 to 14 membered heteroaryl are

-   -   wherein     -   R¹⁰⁵ is at each occurrence H, C₁₋₃₀-alkyl, C₂₋₃₀-alkenyl or         C₂₋₃₀-alkynyl or halogen,     -   R¹⁰⁴ is at each occurrence H or C₁₋₃₀-alkyl.     -   C₆₋₂₆-arylene is a 6 to 26 membered monocyclic or polycyclic,         such as dicyclic, tricyclic, tetracyclic, pentacyclic or         hexacyclic ring system, wherein the rings are either condensed         to each other or connected via a double bond, which         C₆₋₂₆-arylene comprises at least one C-aromatic ring, and which         C₆₋₂₆-arylene may also comprise non-aromatic rings, which         non-aromatic rings may comprise heteroatoms such as O, S, Se,         Te, Si, N and Ge, and which C-aromatic rings or non-aromatic         ring may be substituted, for example by C₁₋₃₀-alkyl, ═O,         ═C(C₁₋₃₀-alkyl)₂ or ═C(CN)₂.

Examples of C₆₋₂₆-arylene are

-   -   wherein     -   R¹⁰⁰ is at each occurrence H, C₁₋₃₀-alkyl, C₂₋₃₀-alkenyl or         C₂₋₃₀-alkynyl or halogen,     -   R¹⁰¹ is at each occurrence H or C₁₋₃₀-alkyl.     -   5 to 20 membered heteroarylene is a 5 to 20 membered monocyclic         or polycyclic, such as dicyclic, tricyclic, tetracyclic,         pentacyclic or hexacyclic ring system, wherein the rings are         either condensed to each other or connected via a double bond,         which 5 to 20 membered heteroarylene comprises at least one         heteroaromatic ring having at least one heteroatom selected from         the group consisting of O, S, Se, N and Te, and which 5 to 20         membered heteroarylene may also comprise aromatic carbon rings         or non-aromatic rings, which non-aromatic ring may comprise         heteroatoms such as O, S, Se, Te, Si, N and Ge, and which         heteroaromatic rings, aromatic carbon rings or non-aromatic         rings may be substituted, for example by C₁₋₃₀-alkyl, ═O,         ═C(C₁₋₃₀-alkyl)₂ or ═C(CN)₂.

Examples of 5 to 20 membered heteroarylene are

-   -   wherein     -   R¹⁰³ is at each occurrence H, C₁₋₃₀-alkyl, C₂₋₃₀-alkenyl or         C₂₋₃₀-alkynyl or halogen,     -   R¹⁰² is at each occurrence H or C₁₋₃₀-alkyl.

Preferred compounds of the present invention comprise at least one unit of formula

-   -   wherein     -   X, Q, R¹, R², L¹, L², n and m are as defined above, and     -   Y is at each occurrence O, S, Se or Te, and     -   R³ is at each occurrence H, C₁₋₃₀-alkyl, C₂₋₃₀-alkenyl or         C₂₋₃₀-alkynyl or halogen.

More preferred compounds of the present invention comprise at least one unit of formula 1A, 1B, 1C or 1D.

Most preferred compounds of the present invention comprise at least one unit of formula 1A.

The compounds of the present invention can be small molecules or polymers.

The compounds of the present invention which are small molecules preferably comprise one or two units of formula 1 or 1′ as defined above.

Small molecules have preferably a weight average molecular weight (M_(w)) of below 1 kDa, more preferably of below 800 Da, and a number average molecular weight (M_(n)) of below 1 kDa, more preferably of below 800 Da.

Preferably, the compounds of the present invention are polymers.

The compounds of the present invention which are polymers preferably comprise at least three units of formula 1 or 1′ as defined above.

The polymers have preferably a weight average molecular weight (M_(w)) of 1 to 10000 kDa and a number average molecular weight (M_(n)) of 1 to 10000 kDa. The polymers of the present invention have more preferably a weight average molecular weight (M_(w)) of 1 to 1000 kDa and a number average molecular weight (M_(n)) of 1 to 100 kDa. The polymers of the present invention have even more preferably a weight average molecular weight (M_(w)) of 5 to 1000 kDa and a number average molecular weight (M_(n)) of 5 to 100 kDa. The polymers of the present invention have still more preferably a weight average molecular weight (M_(w)) of 10 to 1000 kDa and a number average molecular weight (M_(n)) of 10 to 100 kDa. The polymers of the present invention have most preferably a weight average molecular weight (M_(w)) of 10 to 100 kDa and a number average molecular weight (M_(n)) of 5 to 60 kDa. The weight average molecular weight (M_(w)) and the number average molecular weight (M_(n)) can be determined by gel permeation chromatography (GPC) e.g. at 80° C. using chlorobenzene or preferably at 150° C. using trichlorobenzene as eluent and a polystyrene as standard.

More preferably, the compounds of the present invention are polymers comprising at least 60% by weight of the units of formula 1 or 1′ based on the weight of the polymer.

Even more preferably, the compounds of the present invention are polymers comprising at least 80% by weight of the units of formula 1 or 1′ based on the weight of the polymer.

Most preferably, the compounds of the present invention are polymers comprising at least 95% by weight of the units of formula 1 or 1′ based on the weight of the polymer.

Preferably, X is at each occurrence O, S or Se. More preferably, X is at each occurrence S or Se. Most preferably, X is at each occurrence S.

Preferably, Y is at each occurrence O, S or Se. More preferably, Y is at each occurrence S or Se. Most preferably, Y is at each occurrence S.

Preferably Q is at each occurrence C or Si. More preferably Q is at each occurrence C.

Preferably, R¹ is at each occurrence selected from the group consisting of H, C₁₋₅₀-alkyl, —[CH₂]_(o)—[R^(a)R^(a)Si—O]_(p)—SiR^(a)R^(a)R^(a), —[CR^(b)R^(b)]_(q)—CR^(b)R^(b)R^(b), C₂₋₅₀-alkenyl and C₂₋₅₀-alkynyl,

-   -   wherein     -   is an integer from 1 to 10,     -   p is an integer from 1 to 40,     -   R^(a) is at each occurrence C₁₋₁₀-alkyl, C₂₋₁₀-alkenyl or         C₂₋₁₀-alkynyl,     -   q is an integer from 1 to 50,     -   R^(b) is at each occurrence H or halogen, with the provisio that         not all R^(b) in —[CR^(b)R^(b)]_(q)—CR^(b)R^(b)R^(b) are H,     -   C₁₋₅₀-alkyl, C₂₋₅₀-alkenyl and C₂₋₅₀-alkynyl can be substituted         with one to four substituents independently selected from the         group consisting of OR^(c), OC(O)—R^(c), C(O)—OR^(c),         C(O)—R^(c), NR^(c)R^(c), NR^(c)—C(O)R^(c), C(O)—NR^(c)R^(c),         N[C(O)R^(c)][C(O)R^(c)], SR^(c), CN, and NO₂,         -   wherein         -   R^(c) is at each occurrence H, C₁₋₂₀-alkyl, C₂₋₁₀-alkenyl or             C₂₋₁₀-alkynyl.

More preferably, R¹ is at each occurrence C₁₋₅₀-alkyl. Most preferably, R¹ is at each occurrence C₆₋₃₀-alkyl.

Preferably, R² is at each occurrence H, C₁₋₃₀-alkyl or halogen. More preferably, R² is at each occurrence H.

Preferably, R³ is at each occurrence H, C₁₋₃₀-alkyl or halogen. More preferably, R³ is at each occurrence H.

Preferably, X, Q, R¹ and R² are at each occurrence the same. If Y and R³ are present, Y and R³ are preferably at each occurrence the same.

Preferably, n is 0, 1 or 2. More preferably, n is 0 or 1. Most preferably, n is 0.

Preferably, m is 0, 1, 2 or 3. More preferably, m is 0, 1 or 2. Most preferably, m is 1.

Preferably, L¹ and L² are independently from each other and at each occurrence selected from the group consisting of C₆₋₂₆-arylene, 5 to 20 membered heteroarylene, and

-   -   C₆₋₂₆-arylene and 5 to 20 membered heteroarylene can be         substituted with one to four substituents R^(d) at each         occurrence selected from the group consisting of C₁₋₃₀-alkyl,         C₂₋₃₀-alkenyl, C₂₋₃₀-alkynyl and halogen,     -   wherein C₆₋₂₆-arylene, optionally substituted with one to four         substituents R^(d), is selected from the group consisting of

-   -   wherein     -   R¹⁰¹ is at each occurrence H or C₁₋₃₀-alkyl,         and     -   wherein 5 to 20 membered heteroarylene, optionally substituted         with one to four substitutents R^(d), are selected from the         group consisting of

-   -   wherein     -   R¹⁰³ is at each occurrence H, C₁₋₃₀-alkyl, C₂₋₃₀-alkenyl or         C₂₋₃₀-alkynyl or halogen,     -   R¹⁰² is at each occurrence H or C₁₋₃₀-alkyl.

More preferably, L¹ and L² are independently from each other and at each occurrence selected from the group consisting of C₆₋₂₆-arylene, 5 to 20 membered heteroarylene

-   -   wherein     -   C₆₋₂₆-arylene and 5 to 20 membered heteroarylene can be         substituted with one to two substituents R^(d) at each         occurrence selected from the group consisting of C₁₋₃₀-alkyl,         C₂₋₃₀-alkenyl, C₂₋₃₀-alkynyl and halogen,     -   wherein C₆₋₂₆-arylene, optionally substituted with one to two         substituents R^(d), are selected from the group consisting of

-   -   wherein     -   R¹⁰¹ is at each occurrence H or C₁₋₃₀-alkyl,         and     -   wherein 5 to 20 membered heteroarylene, optionally substituted         with one to two substitutents R^(d), are selected from the group         consisting of

-   -   wherein     -   R¹⁰³ is at each occurrence H, C₁₋₃₀-alkyl, C₂₋₃₀-alkenyl or         C₂₋₃₀-alkynyl or halogen,     -   R¹⁰² is at each occurrence H or C₁₋₃₀-alkyl.

Even more preferably, L¹ and L² are independently from each other and at each occurrence selected from the group consisting of C₆₋₂₆-arylene, 5 to 20 membered heteroarylene

-   -   wherein     -   C₆₋₂₆-arylene and 5 to 20 membered heteroarylene can be         substituted with one to two substituents R^(d) at each         occurrence selected from the group consisting of C₁₋₃₀-alkyl,         C₂₋₃₀-alkenyl, C₂₋₃₀-alkynyl and halogen,     -   wherein C₆₋₂₆-arylene, optionally substituted with one to two         substituents R^(d), is

-   -   wherein     -   R¹⁰¹ is at each occurrence H or C₁₋₃₀-alkyl,         and     -   wherein 5 to 20 membered heteroarylene, optionally substituted         with one to two substitutents R^(d), are selected from the group         consisting of

-   -   wherein     -   R¹⁰³ is at each occurrence H, C₁₋₃₀-alkyl, C₂₋₃₀-alkenyl or         C₂₋₃₀-alkynyl or halogen,     -   R¹⁰² is at each occurrence H or C₁₋₃₀-alkyl.

Most preferably, L¹ and L² are independently from each other a 5 to 20 membered heteroarylene

-   -   wherein     -   5 to 20 membered heteroarylene can be substituted with one to         two substituents R^(d) at each occurrence selected from the         group consisting of C₁₋₃₀-alkyl, C₂₋₃₀-alkenyl, C₂₋₃₀-alkynyl         and halogen,     -   wherein 5 to 20 membered heteroarylene, optionally substituted         with one to two substitutents R^(d), is

Particular preferred compounds of the present invention are polymers comprising at least one unit of formula 1 or 1′, wherein n=0, and which are of formula

-   -   wherein     -   X is at each occurrence O, S or Se,     -   Q is at each occurrence C or Si,     -   R¹ is at each occurrence C₁₋₅₀-alkyl,     -   R² is at each occurrence H,     -   m is 0, 1 or 2,     -   L² is at each occurrence selected from the group consisting of         C₆₋₂₆-arylene, 5 to 20 membered heteroarylene         -   wherein         -   C₆₋₂₆-arylene and 5 to 20 membered heteroarylene can be             substituted with one to two substituents R^(d) at each             occurrence selected from the group consisting of             C₁₋₃₀-alkyl, C₂₋₃₀-alkenyl, C₂₋₃₀-alkynyl and halogen,         -   wherein C₆₋₂₆-arylene, optionally substituted with one to             two substituents R^(d), is

-   -   -   wherein         -   R¹⁰¹ is at each occurrence H or C₁₋₃₀-alkyl,

    -   and         -   wherein 5 to 20 membered heteroarylene, optionally             substituted with one to two substitutents R^(d), are             selected from the group consisting of

-   -   -   wherein         -   R¹⁰³ is at each occurrence H, C₁₋₃₀-alkyl, C₂₋₃₀-alkenyl or             C₂₋₃₀-alkynyl or halogen,         -   R¹⁰² is at each occurrence H or C₁₋₃₀-alkyl.

More particular preferred compounds of the present invention are polymers comprising at least one unit of formula 1 or 1′, wherein n=0 and which are of formula

-   -   wherein     -   X is at each occurrence O, S or Se,     -   Q is at each occurrence C or Si,     -   R¹ is at each occurrence C₁₋₅₀-alkyl,     -   R² is at each occurrence H,     -   m is 0, 1 or 2,     -   L² is at each occurrence selected from the group consisting of         C₆₋₂₆-arylene, 5 to 20 membered heteroarylene         -   wherein         -   C₆₋₂₆-arylene and 5 to 20 membered heteroarylene can be             substituted with one to two substituents R^(d) at each             occurrence selected from the group consisting of             C₁₋₃₀-alkyl, C₂₋₃₀-alkenyl, C₂₋₃₀-alkynyl and halogen,         -   wherein C₆₋₂₆-arylene, optionally substituted with one to             two substituents R^(d), is

-   -   -   wherein         -   R¹⁰¹ is at each occurrence H or C₁₋₃₀-alkyl,

    -   and         -   wherein 5 to 20 membered heteroarylene, optionally             substituted with one to two substitutents R^(d), are             selected from the group consisting of

-   -   -   wherein         -   R¹⁰³ is at each occurrence H, C₁₋₃₀-alkyl, C₂₋₃₀-alkenyl or             C₂₋₃₀-alkynyl or halogen,         -   R¹⁰² is at each occurrence H or C₁₋₃₀-alkyl.

Even more particular preferred compounds of the present invention are polymers comprising at least one unit of formula

-   -   wherein     -   X is at each occurrence O, S or Se,     -   Q is at each occurrence C or Si,     -   R¹ is at each occurrence C₁₋₅₀-alkyl,     -   R² is at each occurrence H,     -   m is 0, 1 or 2,     -   L² is at each occurrence selected from the group consisting of         C₆₋₂₆-arylene, 5 to 20 membered heteroarylene         -   wherein         -   C₆₋₂₆-arylene and 5 to 20 membered heteroarylene can be             substituted with one to two substituents R^(d) at each             occurrence selected from the group consisting of             C₁₋₃₀-alkyl, C₂₋₃₀-alkenyl, C₂₋₃₀-alkynyl and halogen,         -   wherein C₆₋₂₆-arylene, optionally substituted with one to             two substituents R^(d), is

-   -   -   wherein         -   R¹⁰¹ is at each occurrence H or C₁₋₃₀-alkyl,

    -   and         -   wherein 5 to 20 membered heteroarylene, optionally             substituted with one to two substitutents R^(d), are             selected from the group consisting of

-   -   -   wherein         -   R¹⁰³ is at each occurrence H, C₁₋₃₀-alkyl, C₂₋₃₀-alkenyl or             C₂₋₃₀-alkynyl or halogen,         -   R¹⁰² is at each occurrence H or C₁₋₃₀-alkyl.

Most particularly preferred compounds of the present invention are polymers comprising at least one unit of formula

-   -   wherein     -   X is at each occurrence O, S or Se,     -   Q is at each occurrence C or Si,     -   R¹ is at each occurrence C₁₋₅₀-alkyl,     -   R² is at each occurrence H,     -   m is 0, 1 or 2,     -   L² is at each occurrence 5 to 20 membered heteroarylene         -   wherein         -   5 to 20 membered heteroarylene can be substituted with one             to two substituents R^(d) which is at each occurrence             halogen,         -   wherein 5 to 20 membered heteroarylene, optionally             substituted with one to two substitutents R^(d), is

Especially preferred compounds of the present invention are polymers comprising at least one unit of formula

-   -   wherein R¹ is at each occurrence C₁₋₅₀-alkyl.

Also part of the present invention, is a process for the preparation of the compounds of the present invention comprising at least one unit of formula

-   -   wherein     -   M1 and M2 are independently of each other an aromatic or         heteroaromatic monocyclic or bicyclic ring system;     -   X is at each occurrence O, S, Se or Te,     -   Q is at each occurrence C, Si or Ge,     -   R¹ is at each occurrence selected from the group consisting of         H, C₁₋₅₀-alkyl,         —[CH₂]_(o)—[OSiR^(a)R^(a)]_(o)—OSiR^(a)R^(a)R^(a),         —[CH₂]_(o)—[R^(a)R^(a)Si—O]_(p)—SiR^(a)R^(a)R^(a),         —[CR^(b)R^(b)]_(q)—CR^(b)R^(b)R^(b), C₂₋₅₀-alkenyl,         C₂₋₅₀-alkynyl, C₅₋₈-cycloalkyl, C₆₋₁₄-aryl and 5 to 14 membered         heteroaryl,         -   wherein         -   is an integer from 0 to 10,         -   p is an integer from 1 to 40,         -   R^(a) is at each occurrence C₁₋₁₀-alkyl, C₂₋₁₀-alkenyl or             C₂₋₁₀-alkynyl,         -   q is an integer from 1 to 50,         -   R^(b) is at each occurrence H or halogen, with the provisio             that not all R^(b) in —[CR^(b)R^(b)]_(q)—CR^(b)R^(b)R^(b)             are H,         -   C₁₋₅₀-alkyl, C₂₋₅₀-alkenyl and C₂₋₅₀-alkynyl can be             substituted with one to four substituents independently             selected from the group consisting of OR^(c), OC(O)—R^(c),             C(O)—OR^(c), C(O)—R^(c), NR^(c)R^(c), NR^(c)—C(O)R^(c),             C(O)—NR^(c)R^(c), N[C(O)R^(c)][C(O)R^(c)], SR^(c), CN,             SiR^(c)R^(c)R^(c), and NO₂,         -   C₅₋₈-cycloalkyl can be substituted with one or two             substituents independently selected from the group             consisting of C₁₋₁₀-alkyl, C₂₋₁₀-alkenyl, C₂₋₁₀-alkynyl,             OR^(c), OC(O)—R^(c), C(O)—OR^(c), C(O)—R^(c), NR^(c)R^(c),             NR^(c)—C(O)R^(c), C(O)—NR^(c)R^(c), N[C(O)R^(c)][C(O)R^(c)],             SR^(c), halogen, CN, SiR^(c)R^(c)R^(c), and NO₂; and one             CH₂-group of C₅₋₈-cycloalkyl can be replaced by O, S, OC(O),             CO, NR^(c) or NR^(c)—CO,         -   C₆₋₁₄-aryl and 5 to 14 membered heteroaryl can be             substituted with one to three substituents independently             selected from the group consisting of C₁₋₁₀-alkyl,             C₂₋₁₀-alkenyl, C₂₋₁₀-alkynyl, OR^(c), OC(O)—R^(c),             C(O)—OR^(c), C(O)—R^(c), NR^(c)R^(c), NR^(c)—C(O)R^(c),             C(O)—NR^(c)R^(c), N[C(O)R^(c)][C(O)R^(c)], SR^(c), halogen,             CN, and NO₂,             -   wherein             -   R^(c) is at each occurrence H, C₁₋₂₀-alkyl,                 C₂₋₁₀-alkenyl or C₂₋₁₀-alkynyl,     -   R² is at each occurrence H, C₁₋₃₀-alkyl, C₂₋₃₀-alkenyl or         C₂₋₃₀-alkynyl or halogen,     -   n is 0, 1, 2, 3 or 4,     -   m is 0, 1, 2, 3 or 4,     -   and     -   L¹ and L² are independently from each other and at each         occurrence selected from the group consisting of C₆₋₂₆-arylene,         5 to 20 membered heteroarylene,

-   -   -   wherein         -   C₆₋₂₆-arylene and 5 to 20 membered heteroarylene can be             substituted with one to four substituents R^(d) at each             occurrence selected from the group consisting of H,             C₁₋₃₀-alkyl, C₂₋₃₀-alkenyl, C₂₋₃₀-alkynyl and halogen, and

-   -   -   can be substituted with one or two substituents at each             occurrence selected from the group consisting of R^(e),             COOR^(e) and CN, wherein R^(e) is at each occurrence             selected from the group consisting of H, C₁₋₃₀-alkyl,             C₂₋₃₀-alkenyl and C₂₋₃₀-alkynyl,

    -   which process comprises the step of treating a compound of         formula

-   -   wherein M1, M2, X, Q, R¹ and R² are as defined for units of         formula 1 or 1′ with acid to afford a compound of formula

-   -   wherein M1, M2, X, Q, R¹ and R² are as defined for the units of         formula 1 and 1′.

The acid can be any acid such as a cation exchanger in hydrogen form, trifluoroacetic acid, acetic acid or p-toluene sulfonic acid. Preferably, the acid is a cation exchanger in hydrogen form, more preferably Amberlyst® 15.

Preferably, the water formed in this step is removed in situ.

The step can be performed in any suitable solvent, for example toluene.

The compounds of the present invention comprising at least one unit of formula 1 or 1′ can be prepared from compounds of formula 3 or 3′ by methods known in the art.

The compounds of the present invention, which are polymers comprising at least a unit of formula 1 or 1′, wherein n=0, and which are units of formula

-   -   wherein     -   M1, M2, X, Q, R¹, R², m and L² are as defined for a formula 1 or         1′,     -   can be prepared by treating a compound of formula

-   -   wherein M1, M2, X, Q, R¹ and R² are as defined for units of         formula 1 or 1′, and     -   Z¹ is at each occurrence selected from h group consisting of         B(OZ^(a))(OZ^(a)), SnZ^(a)Z^(a)Z^(a),

-   -   wherein Z^(a) is at each occurrence H or C₁₋₄-alkyl,     -   with a compound of formula         LG²-L²-LG²     -   wherein L² is as defined in units of formula 1 and 1′, and LG²         is at each occurrence a leaving group.

For example, the compounds of the present invention, which are polymers comprising at least a unit of formula 1 or 1′, wherein n and m=0 and which units are of formula

-   -   wherein     -   M1, M2, X, Q, R¹ and R² are defined as in formula 1 or 1,     -   can be prepared by treating a compound of formula

-   -   wherein M1, M2, X, Q, R¹ and R² are defined as in formula 1 or         1′, and     -   Z¹ is at each occurrence selected from the group consisting of         B(OZ^(a))(OZ^(a)), SnZ^(a)Z^(a)Z^(a),

-   -   wherein Z^(a) is at each occurrence H or C₁₋₄-alkyl,     -   with a compound of formula

-   -   wherein M1, M2, X, Q, R¹ and R² are defined as in formula 1 or         1′, and LG³ is a leaving group.

Preferably, Z¹ is at each occurrence selected from the group consisting of SnZ^(a)Z^(a)Z^(a) and

-   -   wherein Z^(a) is at each occurrence H or C₁₋₄-alkyl.

More preferably, Z¹ is at each occurrence SnZ^(a)Z^(a)Z^(a), wherein Z^(a) is at each occurrence C₁₋₄-alkyl.

Preferably, LG² and LG³ are independently and at each occurrence halogen, more preferably Cl or Br.

The reaction is usually performed in the presence of a catalyst, preferably a Pd catalyst such as Pd(P(Ph)₃)₄, Pd(OAc)₂ and tris(dibenzylideneacetone)dipalladium. Depending on the Pd catalyst, the reaction may also require the presence of a phosphine ligand such as P(Ph)₃, P(o-tolyl)₃ and P(tert-Bu)₃. The reaction is also usually performed at elevated temperatures, such as at temperatures in the range of 40 to 250° C., preferably 60 to 200° C. The reaction can be performed in the presence of any suitable solvent such as tetrahydrofuran, toluene or chlorobenzene. The reaction is usually performed under inert gas.

When Z¹ is at each occurrence SnZ^(a)Z^(a)Z^(a), wherein Z^(a) is at each occurrence C₁₋₄-alkyl, the reaction is usually performed in the presence of a catalyst, preferably a Pd catalyst such as Pd(P(Ph)₃)₄ and tris(dibenzylideneacetone)dipalladium.

The compounds of formula

-   -   wherein M1, M2, X, Q, R¹ and R² are as defined for units of         formula 1 and 1′, and     -   Z¹ is at each occurrence selected from the group consisting of         B(OZ^(a))(OZ^(a)), SnZ^(a)Z^(a)Z^(a),

-   -   wherein Z^(a) is at each occurrence H or C₁₋₄-alkyl,     -   can be prepared by treating a compound of formula

-   -   wherein M1, M2, X, Q, R¹ and R² are as defined for units of         formula 1 or 1′,     -   with a base and Z¹-LG¹,     -   wherein Z¹ is as defined in formula 2 or 2′, and LG¹ is a         leaving group.

The base can be any suitable base such as n-butyl lithium.

Preferably, if Z¹ is SnZ^(a)Z^(a)Z^(a), LG¹ is at each occurrence halogen, more preferably Br.

The compounds of formula 4, wherein M1, Q, X, R¹ and R² are as defined for the units of formula 1, can be prepared as follows

The compounds of formula 8, wherein M1, Q, X and R¹ are as defined for the units of formula 1 and R² is H, can be prepared as follows

The compounds of formula 4′, wherein M2, Q, X, R¹ and R² are as defined for the units of formula 1′ and can be prepared as follows:

The compounds of formula 8′, wherein M2, Q, X and R¹ are as defined for the units of formula 1′ and R² is H, can be prepared as follows

The compounds 10 and 10′ can be prepared by methods known in the art, for example as described in W. Zhang, J. Smith, S. E. Watkins, R. Gysel, M. McGehee, A. Salleo, J. Kirkpatrick, S. Ashraf, T. Anthopoulos, M. Heeney, I. McCulloch, J. Am. Chem. Soc. 2010, 132, 11437.

Also part of the present invention are compounds of formula

-   -   wherein M1, M2, X, Q, R¹ and R² are as defined for the units of         formula 1 or 1′.

Preferred compounds of formula 3 or 3′ are of formula

-   -   wherein     -   X, Q, R¹ and R² are as defined above, and     -   Y is at each occurrence O, S, Se or Te, and     -   R³ is at each occurrence H, C₁₋₃₀-alkyl, C₂₋₃₀-alkenyl or         C₂₋₃₀-alkynyl or halogen.

More preferred compounds of formula 3 or 3′ are compounds of formula 3A, 3B, 3C, 3D, 3′A, 3′B and 3′C.

Even more preferred compounds of formula 3 or 3′ are compounds of formula 3A, 3B, 3C and 3D.

Most preferred compounds of formula 3 or 3′ are compounds of formula 3A.

Also part of the invention is an electronic device comprising the compounds of the present invention.

The electronic device can be an organic photovoltaic device (OPVs), an organic field-effect transistor (OFETs), an organic light emitting diode (OLEDs) or an organic photodiode (OPDs).

Preferably, the electronic device is an organic photovoltaic device (OPVs), an organic field-effect transistor (OFETs) or an organic photodiode (OPDs).

More preferably, the electronic device is an organic field effect transistor (OFET).

Usually, an organic field effect transistor comprises a dielectric layer, a semiconducting layer and a substrate. In addition, an organic field effect transistor usually comprises a gate electrode and source/drain electrodes.

Preferably, the semiconducting layer comprises the compounds of the present invention. The semiconducting layer can have a thickness of 5 to 500 nm, preferably of 10 to 100 nm, more preferably of 20 to 50 nm.

The dielectric layer comprises a dielectric material. The dielectric material can be silicon dioxide or aluminium oxide, or, an organic polymer such as polystyrene (PS), poly(methylmethacrylate) (PMMA), poly(4-vinylphenol) (PVP), poly(vinyl alcohol) (PVA), benzocyclobutene (BCB), fluoropolymers or polyimide (PI). The dielectric layer can have a thickness of 10 to 2000 nm, preferably of 50 to 1000 nm, more preferably of 100 to 800 nm.

The dielectric layer can in addition to the dielectric material comprise a self-assembled monolayer of organic silane derivates or organic phosphoric acid derivatives. An example of an organic silane derivative is octyltrichlorosilane. An examples of an organic phosphoric acid derivative is octyldecylphosphoric acid. The self-assembled monolayer comprised in the dielectric layer is usually in contact with the semiconducting layer.

The source/drain electrodes can be made from any suitable organic or inorganic source/drain material. Examples of inorganic source/drain materials are gold (Au), silver (Ag) or copper (Cu), as well as alloys comprising at least one of these metals. The source/drain electrodes can have a thickness of 1 to 100 nm, preferably from 20 to 70 nm.

The gate electrode can be made from any suitable gate material such as highly doped silicon, aluminium (AI), tungsten (W), indium tin oxide or gold (Au), or alloys comprising at least one of these metals. The gate electrode can have a thickness of 1 to 200 nm, preferably from 5 to 100 nm.

The substrate can be any suitable substrate such as glass, or a plastic substrate such as polyethersulfone, polycarbonate, polysulfone, polyethylene terephthalate (PET) and polyethylene naphthalate (PEN). Depending on the design of the organic field effect transistor, the gate electrode, for example highly doped silicon can also function as substrate.

The organic field effect transistor can be prepared by methods known in the art.

For example, a top-gate bottom-contact organic field effect transistor can be prepared as follows: Source/drain electrodes can be formed by evaporating a suitable source/drain material, for example gold (Au), on photo-lithographically defined electrodes on a suitable substrate, for example a glass substrate. The electrodes can be treated with a suitable electrode treatment material such as pentafluorobenzenethiol. The semiconducting layer can be formed by depositing a solution of the compounds of the present invention, for example by spin-coating, on the source/drain electrodes. A dielectric layer can be formed by applying, for example, by spin-coating, a solution of a suitable dielectric material such as fluoropolymer, on the semiconducting layer. The gate electrode of a suitable gate material, for example gold (Au), can be evaporated through a shadow mask on the dielectric layer.

Also part of the invention is the use of the compounds of the present invention as semiconducting material.

The compounds of the present invention show high charge carrier mobilities. In addition, the compounds of the present invention show a high stability. Furthermore, the polymers of the present invention are compatible with liquid processing techniques.

FIG. 1 shows the transfer characteristics of an organic field effect transistor comprising polymer P1 as semiconducting material

FIG. 2 shows the output characteristics of an organic field effect transistor comprising polymer P1 as semiconducting material.

EXAMPLES Example 1

Preparation of Compound 11a

Compound 13a: A solution of LDA in THF (1 M) (67.4 mL, 67.4 mmol) was added dropwise to 3-bromothiophene (14a) (10 g, 61.3 mmol) in 300 mL THF at 0° C. After stirring the mixture for 1 h, DMF (5.2 mL, 67.4 mmol) was added to the mixture at 0° C. and the mixture was warmed up to room temperature. After stirring for 4 h, water (100 mL) was added to the mixture and it was extracted with ether for three times. The organic phases were collected, dried over magnesium sulfate, filtered and concentrated under vacuum. The product was purified by column chromatography on silica gel with hexane/ethyl acetate (50:1) as eluent to give compound 13a as a yellow oil. Yield: 11.0 g (94%). ¹H NMR (400 MHz; CDCl₃): δ 7.15 (d, 1H, J=4.8 Hz), 7.73 (dd, 1H, J=1.2, 5.2 Hz), 9.98 (d, 1H, J=1.2 Hz); ¹³C NMR (100 MHz; CDCl₃): δ 120.38, 132.03, 134.87, 136.90, 183.03.

Compound 12a: 3-bromothiophene-2-carbaldehyde (13a) (11 g, 57.6 mmol) was dissolved in methanol (300 ml) and cooled to 0° C. NaBH₄ (3.3 g, 86.4 mmol) was added in small portions to the mixture and stirred for 4 h. Water (100 mL) was added to the mixture and it was extracted with ether for three times. The organic phases were collected, dried over magnesium sulfate, filtered and concentrated under vacuum. The product was purified by column chromatography on silica gel with hexane/ethyl acetate (10:1) as eluent to give compound 12a as a colourless oil. Yield: 10.9 g (98%). ¹H NMR (700 MHz, CDCl₃) δ 7.28 (d, 1H, J=5.2 Hz), 6.98 (d, 1H, J=5.2 Hz), 4.83 (d, 2H, J=6.4 Hz), 2.98 (s, br, 1H); ¹³C NMR (176 MHz, CDCl₃) δ 138.31, 130.13, 125.48, 108.89, 58.96.

Compound 11a: Imidazole (8.82 g, 129.5 mmol) was added to a solution of (3-bromothiophen-2-yl)methanol (12a) (10 g, 51.8 mmol) and triisopropylchlorosilane (11.98 g, 62.16 mmol) in dichloromethane. The mixture was stirred for 12 h, diluted with saturated aq. NH4Cl, extracted with EtOAc, washed with brine and concentrated in vacuo. The residue was purified by column chromatography on silica gel (eluent: Petroleum ether/ethyl acetate=50:1) to provide compound 11a as a colorless solid (17.74 g, 98% yield). ¹HNMR (700 MHz, CDCl₃) δ 7.21 (d, J=5.3 Hz, 1H), 6.92 (d, J=5.3 Hz, 1H), 4.92 (s, 2H), 1.22-1.18 (m, 3H), 1.12 (s, 18H); ¹³CNMR (176 MHz, CDCl₃) δ 140.83, 129.60, 124.39, 105.30, 61.23, 18.01, 12.01.

Example 2

Preparation of Polymer P1 Comprising a Unit of Formula 1A

Compound 10a and compound 9a were synthesized as described in W. Zhang, J. Smith, S. E. Watkins, R. Gysel, M. McGehee, A. Salleo, J. Kirkpatrick, S. Ashraf, T. Anthopoulos, M. Heeney, I. McCulloch, J. Am. Chem. Soc. 2010, 132, 11437.

Compound 8a: 4,4,9,9-tetrahexadecyl-4,9-dihydro-s-indaceno[1,2-b:5,6-b′]dithiophene (9a) (10 g, 8.59 mmol) was dissolved in anhydrous THF (100 mL) and cooled down to −78′ C under argon, n-butyllithium solution (2.5M, 8.59 mL) was added dropwise and the mixture was warmed up to 0° C. and stirred for 30 min. The mixture was cooled down to −78° C. again and then 1 mL of DMF was added dropwise into the solution and the mixture was warmed up to room temperature and stirred for another 6 hours. Water (100 mL) was added to the mixture and it was extracted with ethyl acetate for three times. The organic phases were collected, dried over magnesium sulfate, filtered and concentrated under vacuum. The product was purified by column chromatography on silica gel with hexane/ethyl acetate (5:1) as eluent to give compound 8a as a yellow solid (9.75 g, 93% yield). ¹H NMR (500 MHz, CDCl₃) δ 9.94 (s, 1H), 7.66 (s, 1H), 7.48 (s, 1H), 2.12-2.10 (m, 8H), 1.36-0.92 (m, 104H), 0.91-0.87 (m, 12H), 0.82-0.65 (m, 8H); ¹³C NMR (126 MHz, CDCl₃) δ 182.96, 156.06, 155.18, 151.40, 145.60, 136.47, 130.41, 115.03, 53.81, 39.12, 32.11, 30.12, 29.84, 29.76, 29.43, 24.32, 22.81, 14.22.

Compound 7a: (3-bromothiophen-2-yl)methoxy)triisopropylsilane (11a) (5 g, 14.3 mmol), prepared as described in example 1, was dissolved in 100 mL anhydrous diethyl ether and cooled to −78° C., n-Butyllithium solution (2.5M, 5.72 mL) was added dropwise stirred for 30 min. 4,4,9,9-tetrahexadecyl-4,9-dihydro-s-indaceno[1,2-b:5,6-b′]dithiophene-2,7-dicarbaldehyde (8a) (5.82 g, 4.76 mmol) dissolved in 50 mL anhydrous diethyl ether was added dropwise into the solution and stirred for further 30 min. The mixture was warmed up to room temperature and stirred overnight. Water (150 mL) was added to the mixture and it was extracted with ethyl acetate for three times. The organic phases were collected, dried over magnesium sulfate, filtered and concentrated under vacuum. The product was purified by column chromatography on silica gel with hexane/dichloromethane (3:1) as eluent to give compound 7a as a brown liquid (6.04 g, 72% yield). ¹H NMR (700 MHz, CDCl₃) δ 7.26 (s, 2H), 7.16 (s, 2H), 7.14 (d, J=5.2 Hz, 2H), 7.03 (d, J=5.2 Hz, 2H), 6.17 (d, J=4.8 Hz, 2H), 4.97 (s, 4H), 2.15-2.10 (m, 8H), 1.23-1.14 (m, 6H), 1.34-0.97 (m, 140H), 0.91-0.82 (m, 12H), 0.81-0.65 (m, 8H); ¹³C NMR (176 MHz, CDCl₃) δ 171.19, 154.24, 152.54, 148.90, 145.69, 141.11, 140.71, 139.54, 135.67, 128.11, 126.40, 124.23, 123.09, 122.98, 119.11, 112.79, 60.43, 31.96, 29.76, 29.71, 29.41, 22.73, 21.08, 18.03, 18.01, 17.99, 17.73, 14.22, 14.16, 12.02, 11.95.

Compound 6a: Compound 7a (10.87 g, 6.17 mmol) was dissolved in 100 mL dichloromethane and then ZnI₂ (0.40 g, 1.24 mmol) was added in one portion, followed by the addition of NaBH₃CN (1.17 g, 18.52 mmol). The mixture was stirred overnight and then quenched by Water (100 mL). The mixture was extracted with ethyl acetate for three times. The organic phases were collected, dried over magnesium sulfate, filtered and concentrated under vacuum. The product was purified by column chromatography on silica gel with hexane as eluent to give compound 6a as a yellow liquid (10.04 g, 94% yield).

¹H NMR (700 MHz, CDCl₃) δ 7.26 (s, 2H), 7.14 (d, J=5.1 Hz, 2H), 6.87 (d, J=5.1 Hz, 2H), 6.65 (s, 2H), 4.96 (s, 4H), 4.14 (s, 4H), 2.15-2.10 (m, 8H), 1.28-1.14 (m, 6H), 1.34-0.96 (m, 140H), 0.91-0.85 (m, 12H), 0.82-0.64 (m, 8H); ¹³C NMR (176 MHz, CDCl₃) δ 154.43, 152.29, 145.05, 139.98, 139.90, 135.51, 134.85, 129.04, 126.84, 123.09, 121.23, 119.68, 112.50, 59.59, 41.36, 39.07, 36.09, 31.96, 29.75, 27.70, 24.24, 22.73, 20.48, 18.62, 17.85, 14.17, 12.97, 11.48.

Compound 5a: Compound 6a (5.58 g, 3.23 mmol) was dissolved in 100 mL THF and TBAF (1M in THF, 8.07 mL) was added into the solution and the mixture was stirred overnight and then quenched by Water (100 mL). The mixture was extracted with ethyl acetate for three times. The organic phases were collected, dried over magnesium sulfate, filtered and concentrated under vacuum. The product was purified by column chromatography on silica gel with hexane/dichloromethane (1:1) as eluent to give compound 5a as a yellow liquid (4.35 g, 95% yield). ¹H NMR (700 MHz, CDCl₃) δ 7.26 (s, 2H), 7.21 (d, J=5.1 Hz, 2H), 6.93 (d, J=5.1 Hz, 2H), 6.69 (s, 2H), 4.83 (s, 4H), 4.21 (s, 4H), 2.14-2.12 (m, 8H), 1.32-0.97 (m, 104H), 0.91-0.84 (m, 12H), 0.82-0.64 (m, 8H); ¹³C NMR (176 MHz, CDCl₃) δ 171.26, 154.54, 152.31, 145.13, 140.06, 137.83, 137.71, 135.49, 129.52, 124.29, 119.71, 112.55, 60.46, 57.78, 53.94, 39.07, 31.96, 30.08, 29.75, 29.71, 29.69, 29.46, 29.41, 24.23, 22.73, 21.09, 17.73, 14.22, 14.17, 12.29.

Compound 4a: Compound 5a (5.22 g, 3.68 mmol) was dissolved in 100 mL dichloromethane and Dess-Martin periodinane (3.91 g, 9.22 mmol) was added into the solution and the mixture was stirred overnight and then slowly quenched by saturated NaHCO₃ solution. The mixture was stirred at room temperature for 30 min and then saturated NaS₂SO₃ solution was added. The mixture was extracted with ethyl acetate for three times. The organic phases were collected, dried over magnesium sulfate, filtered and concentrated under vacuum. The product was purified by column chromatography on silica gel with hexane/dichloromethane (1:1) as eluent to give compound 4a as a yellow solid (4.52 g, 87% yield). ¹H NMR (700 MHz, CDCl₃) δ 10.13 (s, 2H), 7.65 (d, J=5.0 Hz, 2H), 7.14 (s, 2H), 7.05 (d, J=5.0 Hz, 2H), 6.74 (s, 2H), 4.56 (s, 4H), 2.13-2.11 (m, 8H), 1.36-0.96 (m, 104H), 0.90-0.86 (m, 12H), 0.83-0.69 (m, 8H); ¹³C NMR (176 MHz, CDCl₃) δ 182.09, 154.69, 152.44, 149.14, 143.00, 141.50, 140.61, 137.85, 135.50, 134.50, 131.27, 131.08, 128.42, 128.26, 53.93, 39.01, 31.90, 30.25, 29.71, 29.73, 29.63, 29.41, 29.49, 24.22, 22.71, 21.39, 17.43, 14.12, 14.10, 12.49.

Compound 3a: 3,3′-((4,4,9,9-tetrahexadecyl-4,9-dihydro-s-indaceno[1,2-b:5,6-b′]dithiophene-2,7-diyl)bis(methylene))bis(thiophene-2-carbaldehyde) (4a) (3.77 g, 2.67 mmol) was dissolved in 100 mL toluene and 5 g Amberlyst-15 was added into the solution and the mixture was refluxed overnight and the water generated in situ was removed by a Dean-Stark Trap. The mixture was filtered, and the filtrate was concentrated under vacuum. The crude product was purified by column chromatography on silica gel with hexane as eluent to give compound 3a as a pale yellow solid (2.28 g, 62% yield). ¹H NMR (700 MHz, CD₂Cl₂) δ 8.37 (s, 2H), 8.31 (s, 2H), 7.52 (s, 2H), 7.51 (d, J=5.3 Hz, 2H), 7.41 (d, J=5.4 Hz, 2H), 2.13-2.11 (m, 8H), 1.34-0.96 (m, 104H), 0.91-0.86 (m, 12H), 0.82-0.69 (m, 8H); ¹³C NMR (176 MHz, CD₂Cl₂). 13C NMR (176 MHz, CDCl3) δ 139.07, 131.37, 127.83, 126.75, 122.52, 122.09, 121.64, 117.43, 111.44, 108.12, 103.46, 99.16, 98.40, 40.43, 24.10, 16.91, 14.67, 14.65, 14.64, 14.61, 14.58, 14.46, 14.35, 14.17, 8.78, 7.68, 0.90.

Compound 2a: Compound 3a (3.42 g, 2.49 mmol) was dissolved in 80 mL THF and cooled to −78° C., n-butyllithium solution (2.5M, 2.49 mL) was added dropwise stirred for 30 min. 6.23 mL Me₃SnCl solution (1M in THF) was added dropwise into the solution and the mixture was warmed up to room temperature and stirred overnight and then quenched by water (80 mL). The mixture was extracted with ethyl acetate for three times. The organic phases were collected, concentrated under vacuum. The product was recrystallized in acetonitrile/dichloromethane to afford compound 2a as a pale yellow solid. (4.02 g, 95% yield). ¹H NMR (500 MHz, CD₂Cl₂) δ 8.36 (s, 1H), 8.32 (s, 2H), 7.53 (s, 2H), 7.50 (s, 2H), 2.53-2.34 (m, 4H), 2.34-2.16 (m, 4H), 1.41-0.95 (m, 104H), 0.93-0.86 (m, 12H), 0.84-0.61 (m, 8H) 0.50 (s, 18H).

Polymer P1: A 2.5 mL microwave vial was charged with compound 2a (0.40 g, 0.233 mmol), 4,7-dibromobenzo[c][1,2,5]thiadiazole (0.068 g, 0.233 mmol), 2 mol % of tris(dibenzylideneacetone)dipalladium (2.9 mg, 0.005 mmol) and tri(o-tolyl) phosphine (6 mg, 0.02 mmol). The vial was sealed and chlorobenzene (1 mL) was added. The obtained solution was degassed with argon for 30 minutes. The vial was subjected to the following reaction conditions in the microwave reactor: 2 minutes at 100° C., 2 minutes at 120° C., 5 minutes at 140° C., 5 minutes at 160° C. and 20 minutes at 180° C. The polymer was endcapped by addition of 0.1 eq. of 2-bromobenzene before the reaction mixture was resubmitted to the microwave reactor, 1 minute at 100° C., 1 minute at 120° C., 2 minutes at 140° C. and 5 minutes at 160° C. The polymeric solution was cooled down and 0.1 eq. of 2-(trimethylstannyl)benzene was added by syringe. The reaction vial was subjected to the previously mentioned temperature scheme to finalize the end-capping reaction. After reaction, the crude polymer was precipitated in methanol and then further purified by Soxhlet extractions with acetone, hexane and chloroform for 24 hours each. Remaining palladium residues were removed by treating a polymeric chloroform solution with an aqueous sodium diethyldithiocarbamate solution for 2 hours at 50° C. under vigorous stirring. Afterwards the organic phase was separated from the aqueous phase and washed several times with water. The polymeric solution was concentrated under reduced pressure and precipitated into cold methanol. Polymer P1 was filtered off and dried under high vacuum for at least 24 hours. ¹H NMR (500 MHz, CDCl₃) δ 8.71 (br, 2H), 8.37 (br, 2H), 8.13 (br, 2H), 7.68 (br, 2H), 7.74 (br, 2H), 2.14-2.10 (br, 8H), 0.95-1.32 (br, 104H), 0.91-0.84 (br, 12H), 0.82-0.61 (br, 8H).

Example 3

Preparation of a Bottom-Contact, Top-Gate Organic Fieldeffect Transistor (OFET) Comprising Polymer P1 as Semiconducting Material

Gold source and drain contacts were evaporated on glass, followed by treatment with pentafluorobenzenethiol. The semiconducting layer was then spin-coated from 10 mg mL⁻¹ solution of polymer P1 in chlorobenzene and Cytop®, a commercially available fluoropolymer, was deposited as gate dielectric. An Ag gate electrode was used. The channel width and length are W=1000 μm and L=30 μm.

The transfer and output characteristics of the OFET were measured.

FIGS. 1 and 2 show the transfer and output characteristics of the OFET.

Field effect mobility was calculated using the standard thin film transistor model in the saturation regime of the device using:

${\mu_{sat} = {\frac{2L}{WC} \cdot \left( \frac{\partial I_{dsat}}{\partial V_{g}} \right)^{2}}},$

-   -   where L, W, and C are the channel length, channel width, and         capacitance of the dielectric, respectively.

The average saturation hole mobility of the OFET was 2.5 cm² V⁻¹ s⁻¹, with an on/off ratio of 2×10⁵ and approximately −17 V threshold voltage. 

The invention claimed is:
 1. Compounds comprising at least one unit of formula

wherein M1 and M2 are independently of each other an aromatic or heteroaromatic monocyclic or bicyclic ring system; X is at each occurrence O, S, Se or Te, Q is at each occurrence C, Si or Ge, R¹ is at each occurrence selected from the group consisting of H, C₁₋₅₀-alkyl, —[CH₂]_(o)—[O—SiR^(a)R^(a)]_(p)—OSiR^(a)R^(a)R^(a), —[CH₂]_(o)—[R^(a)R^(a)Si—O]_(p)—SiR^(a)R^(a)R^(a), —[CR^(b)R^(b)]_(q)—CR^(b)R^(b)R^(b), C₂₋₅₀-alkenyl, C₂₋₅₀-alkynyl, C₅₋₈-cycloalkyl, C₆₋₁₄-aryl and 5 to 14 membered heteroaryl, wherein is an integer from 0 to 10, p is an integer from 1 to 40, R^(a) is at each occurrence C₁₋₁₀-alkyl, C₂₋₁₀-alkenyl or C₂₋₁₀-alkynyl, q is an integer from 1 to 50, R^(b) is at each occurrence H or halogen, with the provisio that not all R^(b) in —[CR^(b)R^(b)]_(q)—CR^(b)R^(b)R^(b) are H, C₁₋₅₀-alkyl, C₂₋₅₀-alkenyl and C₂₋₅₀-alkynyl can be substituted with one to four substituents independently selected from the group consisting of OR^(c), OC(O)—R^(c), C(O)—OR^(c), C(O)—R^(c), NR^(c)R^(c), NR^(c)—C(O)R^(c), C(O)—NR^(c)R^(c), N[C(O)R^(c)][C(O)R^(c)], SR^(c), CN, —SiR^(c)R^(c)R^(c) and NO₂, C₅₋₈-cycloalkyl can be substituted with one or two substituents independently selected from the group consisting of C₁₋₁₀-alkyl, C₂₋₁₀-alkenyl, C₂₋₁₀-alkynyl, OR^(c), OC(O)—R^(c), C(O)—OR^(c), C(O)—R^(c), NR^(c)R^(c), NR^(c)—C(O)R^(c), C(O)—NR^(c)R^(c), N[C(O)R^(c)][C(O)R^(c)], SR^(c), halogen, CN, —SiR^(c)R^(c)R^(c) and NO₂; and one CH₂-group of C₅₋₈-cycloalkyl can be replaced by O, S, OC(O), CO, NR^(c) or NR^(c)—CO, C₆₋₁₄-aryl and 5 to 14 membered heteroaryl can be substituted with one to three substituents independently selected from the group consisting of C₁₋₁₀-alkyl, C₂₋₁₀-alkenyl, C₂₋₁₀-alkynyl, OR^(c), OC(O)—R^(c), C(O)—OR^(c), C(O)—R^(c), NR^(c)R^(c)NR^(c)—C(O)R^(c), C(O)—NR^(c)R^(c), N[C(O)R^(c)][C(O)R^(c)], SR^(c), halogen, CN, and NO₂, wherein R^(c) is at each occurrence H, C₁₋₂₀-alkyl, C₂₋₁₀-alkenyl or C₂₋₁₀-alkynyl, R² is at each occurrence H, C₁₋₃₀-alkyl, C₂₋₃₀-alkenyl or C₂₋₃₀-alkynyl or halogen, n is 0, 1, 2, 3 or 4, m is 0, 1, 2, 3 or 4, and L¹ and L² are independently from each other and at each occurrence selected from the group consisting of C₆₋₂₆-arylene, 5 to 20 membered heteroarylene,

wherein C₆₋₂₆-arylene and 5 to 20 membered heteroarylene can be substituted with one to four substituents R^(d) at each occurrence selected from the group consisting of H, C₁₋₃₀-alkyl, C₂₋₃₀-alkenyl, C₂₋₃₀-alkynyl and halogen, and

 and can be substituted with one or two substituents at each occurrence selected from the group consisting of R^(e), COOR^(e) and CN, wherein R^(e) is at each occurrence selected from the group consisting of H, C₁₋₃₀-alkyl, C₂₋₃₀-alkenyl and C₂₋₃₀-alkynyl.
 2. The compounds of claim 1 comprising at least one unit of formula

wherein X, Q, R¹, R², L¹, L², n and m are as defined in claim 1, Y is at each occurrence O, S, Se or Te, and R³ is at each occurrence H, C₁₋₃₀-alkyl, C₂₋₃₀-alkenyl or C₂₋₃₀-alkynyl or halogen.
 3. The compounds of claim 1, wherein the compound is a polymer.
 4. The compounds of claim 1, wherein X is 0, S or Se.
 5. The compounds of claim 1, wherein Q is C or Si.
 6. The compounds of claim 1, wherein R¹ is at each occurrence selected from the group consisting of H, C₁₋₅₀-alkyl, —[CH₂]_(o)—[R^(a)R^(a)Si—O]_(p)—SiR^(a)R^(a)R^(a), —[CR^(b)R^(b)]_(q)CR^(b)R^(b), C₂₋₅₀-alkenyl and C₂₋₅₀-alkynyl, wherein o is an integer from 1 to 10, p is an integer from 1 to 40, R^(a) is at each occurrence C₁₋₁₀-alkyl, C₂₋₁₀-alkenyl or C₂₋₁₀-alkynyl, q is an integer from 1 to 50, R^(b) is at each occurrence H or halogen, with the provisio that not all R^(b) in —[CR^(b)R^(b)]_(q)—CR^(b)R^(b)R^(b) are H, C₁₋₅₀-alkyl, C₂₋₅₀-alkenyl and C₂₋₅₀-alkynyl can be substituted with one to four substituents independently selected from the group consisting of OR^(c), OC(O)—R^(c), C(O)—OR^(c), C(O)—R^(c), NR^(c)R^(c)NR^(c)—C(O)R^(c), C(O)—NR^(c)R^(c), N[C(O)R^(c)][C(O)R^(c)], SR^(c), CN, and NO₂, wherein R^(c) is at each occurrence H, C₁₋₂₀-alkyl, C₂₋₁₀-alkenyl or C₂₋₁₀-alkynyl.
 7. The compounds of claim 1, wherein R¹ is at each occurrence C₁₋₅₀-alkyl.
 8. The compounds of claim 1, wherein R² is at each occurrence H, C₁₋₃₀-alkyl or halogen.
 9. The compounds of claim 1, wherein m is 0, 1 or
 2. 10. The compounds of claim 1, wherein n is
 0. 11. The compounds of claim 1, wherein L¹ and L² are independently from each other and at each occurrence selected from the group consisting of C₆₋₂₆-arylene, 5 to 20 membered heteroarylene, and

wherein C₆₋₂₆-arylene and 5 to 20 membered heteroarylene can be substituted with one to four substituents R^(d) at each occurrence selected from the group consisting of C₁₋₃₀-alkyl, C₂₋₃₀-alkenyl, C₂₋₃₀-alkynyl and halogen, wherein C₆₋₂₆-arylene, optionally substituted with one to four substituents R^(d), is selected from the group consisting of

wherein R¹⁰¹ is at each occurrence H or C₁₋₃₀-alkyl, and wherein 5 to 20 membered heteroarylene, optionally substituted with one to four substitutents R^(d), are selected from the group consisting of

wherein R¹⁰³ is at each occurrence H, C₁₋₃₀-alkyl, C₂₋₃₀-alkenyl or C₂₋₃₀-alkynyl or halogen, R¹⁰² is at each occurrence H or C₁₋₃₀-alkyl.
 12. A process for the preparation of the compounds of claim 1 comprising at least one unit of formula

wherein M1 and M2 are independently of each other an aromatic or heteroaromatic monocyclic or bicyclic ring system; X is at each occurrence O, S, Se or Te, Q is at each occurrence C, Si or Ge, R¹ is at each occurrence selected from the group consisting of H, C₁₋₅₀-alkyl, —[CH₂]_(o)—[O—SiR^(a)R^(a)]_(p)—OSiR^(a)R^(a)R^(a), —[CH₂]_(o)—[R^(a)R^(a)Si—O]_(p)—SiR^(a)R^(a)R^(a), —[CR^(b)R^(b)]_(q)—CR^(b)R^(b)R^(b), C₂₋₅₀-alkenyl, C₂₋₅₀-alkynyl, C₅₋₈-cycloalkyl, C₆₋₁₄-aryl and 5 to 14 membered heteroaryl, wherein o is an integer from 0 to 10, p is an integer from 1 to 40, R^(a) is at each occurrence C₁₋₁₀-alkyl, C₂₋₁₀-alkenyl or C₂₋₁₀-alkynyl, q is an integer from 1 to 50, R^(b) is at each occurrence H or halogen, with the provisio that not all R^(b) in —[CR^(b)R^(b)]_(q)—CR^(b)R^(b)R^(b) are H, C₁₋₅₀-alkyl, C₂₋₅₀-alkenyl and C₂₋₅₀-alkynyl can be substituted with one to four substituents independently selected from the group consisting of OR^(c), OC(O)—R^(c), C(O)—OR^(c), C(O)—R^(c), NR^(c)R^(c), NR^(c)—C(O)R^(c), C(O)—NR^(c)R^(c), N[C(O)R^(c)][C(O)R], SR^(c), CN, —SiR^(c)R^(c)R^(c) and NO₂, C₅₋₈-cycloalkyl can be substituted with one or two substituents independently selected from the group consisting of C₁₋₁₀-alkyl, C₂₋₁₀-alkenyl, C₂₋₁₀-alkynyl, OR^(c), OC(O)—R^(c), C(O)—OR^(c), C(O)—R^(c), NR^(c)R^(c), NR^(c)—C(O)R^(c), C(O)—NR^(c)R^(c), N[C(O)R^(c)][C(O)R], SR^(c), halogen, CN, —SiR^(c)R^(c)R^(c) and NO₂; and one CH₂-group of C₅₋₈-cycloalkyl can be replaced by O, S, OC(O), CO, NR^(c) or NR^(c)—CO, C₆₋₁₄-aryl and 5 to 14 membered heteroaryl can be substituted with one to three substituents independently selected from the group consisting of C₁₋₁₀-alkyl, C₂₋₁₀-alkenyl, C₂₋₁₀-alkynyl, OR^(c), OC(O)—R^(c), C(O)—OR^(c), C(O)—R^(c), NR^(c)R^(c), NR^(c)—C(O)R^(c), C(O)—NR^(c)R^(c), N[C(O)R^(c)][C(O)R^(c)], SR^(c), halogen, CN, and NO₂, wherein R^(c) is at each occurrence H, C₁₋₂₀-alkyl, C₂₋₁₀-alkenyl or C₂₋₁₀-alkynyl, R² is at each occurrence H, C₁₋₃₀-alkyl, C₂₋₃₀-alkenyl or C₂₋₃₀-alkynyl or halogen, n is 0, 1, 2, 3 or 4, m is 0, 1, 2, 3 or 4, and L¹ and L² are independently from each other and at each occurrence selected from the group consisting of C₆₋₂₆-arylene, 5 to 20 membered heteroarylene,

wherein C₆₋₂₆-arylene and 5 to 20 membered heteroarylene can be substituted with one to four substituents R^(d) at each occurrence selected from the group consisting of H, C₁₋₃₀-alkyl, C₂₋₃₀-alkenyl, C₂₋₃₀-alkynyl and halogen, and

 and can be substituted with one or two substituents at each occurrence selected from the group consisting of R^(e), COOR^(e) and CN, wherein R^(e) is at each occurrence selected from the group consisting of H, C₁₋₃₀-alkyl, C₂₋₃₀-alkenyl and C₂₋₃₀-alkynyl, which process comprises the step of treating a compound of formula

wherein M1, M2, X, Q, R¹ and R² are as defined for units of formula 1 and 1′, with acid to afford a compound of formula

wherein M1, M2, X, Q, R¹ and R² are as defined for the units of formula 1 and 1′.
 13. Compounds of formula

wherein M1 and M2 are independently of each other an aromatic or heteroaromatic monocyclic or bicyclic ring system; X is at each occurrence O, S, Se or Te, Q is at each occurrence C, Si or Ge, R¹ is at each occurrence selected from the group consisting of H, C₁₋₅₀-alkyl, —[CH₂]_(o)—[O—SiR^(a)R^(a)]_(p)—OSiR^(a)R^(a)R^(a), —[CH₂]_(o)—[R^(a)R^(a)Si—O]_(p)—SiR^(a)R^(a)R^(a), —[CR^(b)R^(b)]_(q)—CR^(b)R^(b)R^(b), C₂₋₅₀-alkenyl, C₂₋₅₀-alkynyl, C₅₋₈-cycloalkyl, C₆₋₁₄-aryl and 5 to 14 membered heteroaryl, wherein is an integer from 0 to 10, p is an integer from 1 to 40, R^(a) is at each occurrence C₁₋₁₀-alkyl, C₂₋₁₀-alkenyl or C₂₋₁₀-alkynyl, q is an integer from 1 to 50, R^(b) is at each occurrence H or halogen, with the provisio that not all R^(b) in —[CR^(b)R^(b)]_(q)—CR^(b)R^(b)R^(b) are H, C₁₋₅₀-alkyl, C₂₋₅₀-alkenyl and C₂₋₅₀-alkynyl can be substituted with one to four substituents independently selected from the group consisting of OR^(c), OC(O)—R^(c), C(O)—OR^(c), C(O)—R^(c), NR^(c)R^(c), NR^(c)—C(O)R^(c), C(O)—NR^(c)R^(c), N[C(O)R^(c)][C(O)R^(c)], SR^(c), CN, —SiR^(c)R^(c)R^(c) and NO₂, C₅₋₈-cycloalkyl can be substituted with one or two substituents independently selected from the group consisting of C₁₋₁₀-alkyl, C₂₋₁₀-alkenyl, C₂₋₁₀-alkynyl, OR^(c), OC(O)—R^(c), C(O)—OR^(c), C(O)—R^(c), NR^(c)R^(c), NR^(c)—C(O)R^(c), C(O)—NR^(c)R^(c), N[C(O)R^(c)][C(O)R], SR^(c), halogen, CN, —SiR^(c)R^(c)R^(c) and NO₂; and one CH₂-group of C₅₋₈-cycloalkyl can be replaced by O, S, OC(O), CO, NR^(c) or NR^(c)—CO, C₆₋₁₄-aryl and 5 to 14 membered heteroaryl can be substituted with one to three substituents independently selected from the group consisting of C₁₋₁₀-alkyl, C₂₋₁₀-alkenyl, C₂₋₁₀-alkynyl, OR^(c), OC(O)—R^(c), C(O)—OR^(c), C(O)—R^(c), NR^(c)R^(c), NR^(c)—C(O)R^(c), C(O)—NR^(c)R^(c), N[C(O)R^(c)][C(O)R^(c)], SR^(c), halogen, CN, and NO₂, wherein R^(c) is at each occurrence H, C₁₋₂₀-alkyl, C₂₋₁₀-alkenyl or C₂₋₁₀-alkynyl, R² is at each occurrence H, C₁₋₃₀-alkyl, C₂₋₃₀-alkenyl or C₂₋₃₀-alkynyl or halogen.
 14. Compounds of claim 13 which are of formula

wherein X, Q, R¹ and R² are as defined in claim 13, and Y is at each occurrence O, S, Se or Te, and R³ is at each occurrence H, C₁₋₃₀-alkyl, C₂₋₃₀-alkenyl or C₂₋₃₀-alkynyl or halogen. 